The prior art uses a sampling device which includes a sampler tube having an internal ball to sample a fluid or liquid. The sampler tube is conventionally lowered into a fluid or liquid and the internal ball which closes off a bottom opening of the sampler tube rises in response to fluid or liquid pressure and allows the fluid or liquid to fill the sampler tube as the tube is lowered into the fluid or liquid product.
While it is preferred to use the sampler tube with a liquid, it is also possible to use it with all types of fluids. The sampling valve of the invention is primarily intended for use in connection with liquid handling.
Specifically, the ball itself does not float on the fluid or the liquid when a liquid is used, but the ball is weighted so that, as the tube descends into the fluid or liquid, the fluid or liquid raises the ball sufficiently so that the fluid or liquid can pass-by the ball between the ball and the inner wall of the sampler tube. After entry of the sampler tube into the fluid or liquid for a predetermined distance, the sampling procedure is then stopped, and the ball drops down through the fluid or liquid in the sampler tube and seals the bottom of the tube to prevent any further entry of fluid or liquid into the sampler tube or exiting of the fluid or liquid from the sampler tube. In effect, the ball acts as a check valve.
Sample mechanisms to sample a fluid or a liquid are well known. One example of a prior art sampler mechanism is a sampler tube of the aforesaid type.
However, using the prior art sampler tube can produce a mess because, after the sample is taken, it then becomes necessary to drain the sample, if it is a liquid, into an open container by manually moving the ball away from the bottom of the sampler tube closure formed by the ball and bottom of the tube and allow the fluid or the liquid to pour freely into an open container. If a fluid is used, perhaps another means of egress is to be used.
Another problem with the prior art sampler tube is the possibility of damage to the health of individuals using the sampler tube due to exposure to irritating liquid as well as other toxic materials vapor.
The sampling devices are generally known as zone samplers. For example, the one-liter sampler is used for use in a four-inch S valve, and there are half-liter samplers also.